Feeding is arguably the most complex skill a newborn infant must master in order to achieve independent survival. The integration of suck-swallow-breath rhythms is essential for development of effective feeding behavior. Patterns of suck-swallow-breath rhythms during feeding become more uniform as preterm infants grow and these rhythms are disrupted in infants with bronchopulmonary dysplasia (BPD). Inability to coordinate these rhythms may be a marker of poor neurologic outcome. Cervical auscultation (CA) with an accelerometer with digital signal processing (DSP) technology can be used to quantitatively compare the sounds of infant feeding by calculating the Variance Index (VI) of swallow-associated sounds. This method has been used to show that the swallow-associated sounds of low-risk preterm infants become more uniform with increasing post-menstrual age. As with other feeding rhythms, this progression is not seen in infants with BPD. No studies have correlated CA/DSP data with developmental outcomes. The objectives of this project are: 1) to identify factors inherent in the development of stability, and sources of variability, of swallow-associated sounds in infant feeding, 2) to correlate CA/DSP measurements of swallow-associated sounds during early rhythmic suckle feeding with long-term neurologic/developmental outcomes, 3) to identify differences in rhythmic suckle feeding of infants with various pathologic conditions and 4) to measure the effects of therapeutic interventions such as speech therapy on swallow-associated sounds. Objectives 1, 2 and 3 will be met with a prospective cohort study following 6 groups of infants, healthy term cohort, HIE term cohort, drug-exposed cohort, low-risk preterm cohort, BPD cohort and a Grade III/IVIVH cohort (n = 25 per group). The infants will be followed from the beginning of oral feeding to two years of life. CA/DSP and biometric data will be collected during feeding. Vis will be compared between groups at various time points and within each group over time. CA/DSP data will be correlated with neurobehavioral and developmental outcome data. By correlating the VI and other DSP parameters with behavioral and developmental data, CA/DSP data may be used to identify infants who are at higher risk of a poor long-term outcome, thus allowing earlier developmental intervention to take place. For objective 4, we will enroll an additional 25 infants with BPD and randomize the total group so that half of the infants (25) receive speech therapy and the other half do not. CA/DSP results will be compared before and after feeding therapy. We hypothesize that if therapy is successful, the VI for the intervention group will approximate the VI for the low-risk preterm infants. By successfully completing these projects, we will increase our understanding of the development of successful feeding behavior and make CA/DSP technology more available as a non-invasive diagnostic technique.